Internal Straight Thread O-Ring Boss Reamer pilot series porting tools profile the MS16142/J514F/J1926 contour. The reamer pilot also sizes the minor diameter per class 2B thread specification. Cutters are heat treated for toughness and durability. All tolerances are held within applicable Mil Specs. All grinding is done between centers to insure concentricity. Coolant Thru Available.Cutters can be altered to meet your requirements.